Herbalife Is Surging

Shares in Herbalife were up as much as 10%, as Pershing Square's Bill Ackman delivers what he said yesterday was the most important presentation of his career on the nutritional supplement company.

Appearing on CNBC Monday afternoon, Ackman reiterated his assertion that the Grand Cayman-based firm's business model doesn't add up, and that its shares were going to zero.

Shares fell $6 yesterday.

Herbalife has gained 33% since December 2012 when Ackman published a 334-page document he said showed the company was a fraud.